1. Field of the Invention
This invention relates to a manual resin extruder for extruding resin to fill flaws in laminated glass.
2. The Problem
Modern automobile windshields are made of laminated glass. Flaws are produced in such windshields by being impacted by stones or other debris, which flaws may take various forms. Usually the flaw occurs only in the outer surface layer of the laminated glass. Such flaw may be simply a bruise causing localized delamination of the outer layer of the glass from the inner layer or layers without any discernible nick or pit. Such impact, on the other hand, may produce a nick or pit which usually is quite small. Because usually all the stresses inherent in a windshield resulting from its manufacture have not been dissipated, an impact may also produce one or more cracks or checks originating at the point of impact. Such cracks or checks may radiate outward from the point of impact. Because of unrelieved stress inherent in a laminated glass sheet, one or more of such cracks or checks may propagate spontaneously at an indeterminate time after the impact if no action is taken to prevent such occurrence.
It is known that spontaneous propagation of cracks from a point of impact on a laminated glass windshield can be prevented by utilizing resin to rebond the surface lamination of the laminated glass to the lamination behind it if such precaution is taken promptly. Resin can be used for the dual purpose of rebonding the surface lamination of the laminated glass to its backing and filling any chip, nick or pit which may have been produced in the outer surface of the surface lamination.
3. Prior Art
Various types of extruders or dispensers have been used for supplying resin to fill flaws in laminated glass, but in general they have been awkward and time-consuming to use and have not been very reliable in effecting consistently satisfactory results.